1. Field of the Invention
This invention relates to a prechamber cup for an internal combustion engine.
2. Description of the Prior Art
A prechamber cup formed by ceramics is shown at pages 889-891 of "CERAMICS FOR HIGH PERFORMANCE APPLICATION-II" published in 1978 by Brook Hill Publishing Company. The above-mentioned prechamber cup is formed of reaction bonded silicon nitride. The main object of making a ceramic prechamber cup is to replace expensive nickel alloys by cheaper, non-strategic materials and to be able to operate the internal combustion engine at high temperatures.
However, it has been found to be necessary to improve the design in making the prechamber cup of ceramics.